SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '527b1168354c4e3e30a5a6566dcdc8fa8c4c8efdf168757a86c6bf51f92027a2' 
  AND token = 'm+4dd2gKyIcrXWXj4R05eYjDJoGqmNATVF2UgbnjTrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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