SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d365ff7b842f9733c6afe1568d932f745242572fbd2c607c390fbbb549f7cce' 
  AND token = 'yo7UYFRczGC2b9wPmOOnpbXdqXmMtEgyPvlxQMzifWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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