Sandbox

SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7b3e613c95c74b8c13636a61cd64cfe981590d146f1ff3eb4ce7b49a3edd0db' 
  AND token = 'mL7/OiDlXsjX90FQfbNQVyKZRRbTV9mMCOzGUZjva9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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