SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dc90b2951bf2c33aa5b4e5f7262737fb9a686a760d27e6bf8bd05b64fc6d71e' 
  AND token = 'C9fmJWyPsgGuQkREqiSTGNjQxjwnwfJjSO2DqbE76KQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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