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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b66d2e36f1a6a923ccd94ce3fc98777604f7f5be2eb8a8ac4cffe6a830fde8dd' 
  AND token = 'kAj7aA2kA8lH0zOsHckqGA07cQbq6IaA4dI9lMFXncw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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