SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b4dfd158cdb6196f5caaf6509c464421ce23d0e79177ac04c0406af4dc5e2e4' 
  AND token = 'tTCCxLRSBstqkzxMrGhe1vjewgzrkECiSpKWagmI6Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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