SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef5720b1040860c81759fc9df3beb45c46475fbb931afb106d9f3b358e6cb142' 
  AND token = 'YmrNzrLQDkyQx9ZYgq0jzP4eDe8Hk6hHygTcbzk1h+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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