SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd26a9c20d979454f22b03fe21e713275deaa7e09b2c67e35818ce38fbc72ce1f' 
  AND token = '2jdEpHoy1dzARaslMxcU2x+8dWqQxeEwG8IAeSrDbV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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