SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf808004b488c62c02397efd0704bc075b03ce7847a745e42d413635152859b9' 
  AND token = 'z7RS364b3z28IsIi2m51XqQq9wEWE9GVQ1b0s/zB9y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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