SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f3b1f94a3a1dc2a6f987d4f8f72673079b1af823ff48ad416aed9b8e5b8a9be' 
  AND token = 'VfhawbWp1P76u1iWqJjH960thrHDKhz9lOBdF/NXxdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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