SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '154209bf98b4238a09b129d5dfdba33383f5165cf0d9d167107b022f39239d65' 
  AND token = '95qmFzArI7PrGQFRZniXRX+AyFAYkrDJXnq8FE4wlFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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