SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f56006706304fd7b3e76713942f82b7e358b97fd8b44eb48aab79aacca529b7' 
  AND token = '3SRepT8qK9+JG/1FkOMvu4Ug0mxCFqeAzeB4Jk1kQ98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}