SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc1d4e74642dc3d53222adbc087f9f5b300e274db0f0329fcd6a0b253ed77610' 
  AND token = 'aS57mOX8JQK1UuWoD82Z8ZfbqweB3H8e17Vpnazf2cQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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