SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '221b368d2a1534af75cf9c14407ee330dc09ef30ce21d7d398c741e3420ca7af' 
  AND token = 'VYcGrhsUOVjQpwsM6bmt4ZqP0osALBJDKEhnMwnHcnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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