SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9ae60e132394fe5cac9a489731a174711b45b6a0325213a435df0008741248b' 
  AND token = 'Boi6lw9VD33+Bl//X46NRVymwBm8AL+p+HSJZKbABsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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