SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1850dcf5bbec5b9400140935e023dc83e5dfa2764128bfb0b527773ccbb1ec0b' 
  AND token = 'mwGjHKGe+qvLEqFmZu6N+vTu++G2rCRzvxDUht9o7TE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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