SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea4cf8357626d75c5e414393beec6aa23eab4ca062a66c54c28db9670aac40fe' 
  AND token = '18LUyr41okknt2D6ThnHowlybc5r1hJmBobjJO5ZGYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00087

JSON explain

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