SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66375d5c469b23cce3992c6a2763defa3466afa3cd80b46b4773edbbe33277a4' 
  AND token = 'LDYdJmtKuHdsLIAYbbyrQLxQV/4Kn15fLnzyI+PBYB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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