SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08a16c223f4576e5a5e710a25fdd4dca16db6c863640bb2b8ba018a83314cac8' 
  AND token = 'iZjH6nfr4zBqhtYumxXXbwWWRWr918myojGC0pUQ8Ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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