SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38ec8e310fa67feb4cf46842c6a7dbaf43b9d48943b2a0859837bfc3c817e12a' 
  AND token = 'IV/Su4+Z3O2lyxI/9PwG8vhZNBzQRpiFahLYwKQgGhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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