SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ccfd87d1f0f1b9dea633a940e3895258d5662a26e889a7aa778ccdcb08e66d5' 
  AND token = '9JwJZvUrsCA7TphG/uvq4dNjqDTZpS6nZgS+uok5nuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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