SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65f8bc640444bff82933232ee5f75df32c4a0a5d518969d4163f964ca26a54dc' 
  AND token = 's2l4iCEsJNvsmD3JaP3dYRv/SxNwm9a7qgOq+SN6E5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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