SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f7ff604769e0bc17f86f3df8ff61d7d926a4328af848841ff13da902d15c161' 
  AND token = 'BGNp1DnDwto//KFB9NBTzLL+KKEX5+LOs8sp/Ma6qJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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