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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '280076dc0b555cd0c2b35f266992e0fd5ed8ba91b1ff6047662de0dd8216eb74' 
  AND token = '5cDp1pfmPzKum0cFhWX9hIUTHKvmqT5L3Ow6eqRFF3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}