SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6cdd08c086676527bee1f8df52b8f504dfa5b118ead826e161461c5e1ac72b90' 
  AND token = 'P0X1eXLN33rtmF39pgqzvl3CO13fZYhjDX+fAZrorzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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