SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34e976d47b288f540df112efd6b2423f996c26b3a85cabb497d0e002ca0aa38f' 
  AND token = 'kT3vGyoUL+1RY1I/pdGSqUOfaqKq4CHyOcpjWFkKAFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00146

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}