SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e52180d14307bb5b502a03f10965bb323326b9be7a6e8b09a76436ec2c831d5' 
  AND token = 'oCPZT9NYmyJAY1+xhYnHqBPw75OCzJ6v/3Y6NEyEgig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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