SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '587e238f8fab84e77761a2be7c63f93d104dbf9ca4888c3f0580000c48870e68' 
  AND token = '4RTwZRejOGnLvtb3UgxMM/vrTqyZm2vggpJXptZ5sFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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