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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28820962ef96883acdb5f9d94eed5d3a1e9f5cd10f15ef64e318bab434f36bcb' 
  AND token = 'D2k11ON2XGqT7dXOwBrVjbPUTQ2XOWPlyDeIPnKqPIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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