SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '402629ade180ac5e95a609c69f6219c1c2bb2f34ed6d5b0772fecfab5c813cf3' 
  AND token = 'vxUlPI87g1/s3IxGRSj1Oxqg/k0ZUQpQOWmBmSBqE5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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