SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28ccab32e932ae463336e3a7c54d213f33f454db41041aeaa9366cb87494ec34' 
  AND token = 'qh3d2WQptXwRSya0bGXM/DZxqyvwtloDJKNVHYVaqO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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