SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddc402eaa039aad792965bbaae79ff411e910ca4debac2299dd41fbfaaaac69a' 
  AND token = 'poD8soFuQpL5TXhnOgncH5bfkIkKm7Rx+cQ5q+i5yyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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