SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65346d1570a6c0377d8dcd30a816c8b3b4a466515e28ef9c840fdc2afc3e595d' 
  AND token = 'dvuVKMVwKQyS7PQqVeJR0/Boe+VAZczWyrfXGyTFrm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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