SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'afa4282c0c1dd714c1a5605d3a3f458e63a9bbe93c46eccc343162e9c56c5a84' 
  AND token = 'ZygyTd2wSotB2iY2du15jhdGIJAfSYSjfxL0ZNC7Gv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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