SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41888612872ade925b89d04ce1f1250fe5c63da31e9d79fccd05f8a2e953642b' 
  AND token = 's/onTeLnllH0ux7TmcR05+pznMX5lpsnzP9oVB6FFK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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