SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5730cc68e6fbbd6ab40c955e8915f2ecff42f70fc9a1dfb18f285cac42c426ad' 
  AND token = 'MDS3AKMt287laUUJ27CSgjop49ebBpiJvr+pA0tew0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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