SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30c59c0bd8535d35823713252829643d4f525a560095bfb815539d23303a0580' 
  AND token = 'RXDRfBzLWb5F5JvBcVPNbamDNRwJYnp+92KLxt1UDl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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