SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd97794b215b577a45546dc622d4ceb5f977788526990fd1840e8cfbd3cd687b2' 
  AND token = 'v5UgpxefkBFKnxeIlNfNbRH6wXv5sZbH0kdPXDWd3q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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