SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8484fa1d09aae17fd45d91d6b579a86609079c98e00a1f48d31754f5e3af2ff7' 
  AND token = 'k6eqd/Rx/XU+nDfJwO5DW4CXOv4GKYphmxTi4bzoOG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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