SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f37c5a5d84b0e411226bed90837e20fc446c9c672372d3aa9cec7e39a5a7812' 
  AND token = 'CB7ZNwqupqrLDVEoDD+EfgoHYMlKQlZxWylkSiLDJV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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