SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2461f11706325b10fa8f6a0a72121a7c666e843b222f9ebc8aac2df9316987c4' 
  AND token = '1Ew84WJF+1huPqAuAd0wBqxyKiU0KpCQJUqi5pk1c3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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