SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51b5da68732c05683975c6938c23272be40797f809498d2f65e654adf8e7154f' 
  AND token = 'zCdpZ4rJNM0gypJ/a8Q+IwuozjCPeU8Vs8pFxPIWGVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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