SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8275020f37d3c8d77ce20e8d0cd9764c6f32dfe0d97411b81c7f49670ca0f90' 
  AND token = 'Aa0TKYQqizZYMhUiVVPmgKIaXHJ5saoca/VxhfRZEbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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