SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48346f3b25b3cdb3b84a247009bf1e1061ac578b9ae9009f7555fdb4204f0e29' 
  AND token = 'OCCnR06whXWxhWURasnMjVKgWiczgwUVqqX0oKYDYak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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