SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c698e13e5abba5d775541998dcbcf2d5a329e5fc9952968a5395212742316f8' 
  AND token = 'Xcc8/xzBp4rozzwo3fIrp9JHb7tdA/f2I2Tob1fmTNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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