SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd135b5bf865a3eb747f4dfca4ed1959aaef6d9687a1470bedaca04f38024301c' 
  AND token = 'alFcGteeLDM5EAKgvC/FEbsl7mMBv/zjG4Bh3JwbyTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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