SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7e4c98abe1a71af2d9ffc40eae16fc52975882c88a2f190df59b47ef2c3e3bc' 
  AND token = 'CuZvNILtzv9Ku+0BLtfwnWY6D3W8gujBmDN0hUUnryU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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