SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1b8ac5fc68f9a54655ef662cfaff0f973e946cdfcf22005a72c50dcfe96797e' 
  AND token = 'GFvbJQjXd/ufm5ytJNJ+9KiZqCBBp2oM0Wy2OOVtULw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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