SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e455c7dd8be8952fae5d079e2d047bb44db1ea8e1aab223e4e1b901e733a54f8' 
  AND token = 'Gzs9j5DMvCd5COlqLweptPzw8JKhyPjXIkOwm2fF6Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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