SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96371d41298821eb96a77f414f3b620b2ef802cd9b107bb91242c37fb4e743e8' 
  AND token = 'x3LXmSjNT1v+2WMASnM7WpUzXt7xiZt5nF/PpIaxpoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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