SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42df8106e0d285949ee964f7df19e4a7231fb5ebffc8071fbb9ae56612ee8264' 
  AND token = 'm9VwCQC/7aTJ/vngF4Vqa/yM5G8gJ1btZlSeIsfJhWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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