SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbfff74edc405926c458b8fffbd4302a63732b21c7711baf372c20fe274cd5a7' 
  AND token = 'EGOHzC9/KDZHp2OJJapE60BvkSjtyrAfnM38nP0ZKRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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