SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e131d18f883fb38735ee0a3ebe397cf0a48fbc0440e4008da47777c8c54c8362' 
  AND token = '5W/SaxNUECKe0pnQhaB33iAxunJh9X4CIhEi/dMgj0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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