SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff5b02db4ef94d1189e904e53db3f7417ca52f72f7bb04bed96ab831861751a8' 
  AND token = 'FghPKKxFpzFJF6/tiJTjoRwvVkfFlFn4jtMNXhtZWN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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