SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '885f8b691ad84745a9f0c4be6bc135e4cf29145faf28d663cc4e2b9ee7a520b6' 
  AND token = 'PMWx2CIEz9G1Jhkx5Gdawhg1/N96Ymt+iYfhsPQnO/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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