SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a9d178707f126f4c1c887ce7edf55929cbbb525aa80441fd57c6516c86052b0' 
  AND token = 'sJrpOoOmcjthW9DqxeRmAQfBf/FP7zjwQSkaKPKYudg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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