SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a49a272b3dcf39f75c87b002a142e514168c34dd9625aa7a83fcd8c618da2d8' 
  AND token = 'LlcEdxdFaSDcdVdqYNkd/Kl0uDjve7uBFgbjUgoAMpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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