SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a33ffba8a36c2ac373b61b029e0c94912e2013fa82552bfc940207ffff16c84' 
  AND token = 'wq1QGqffNbbhtIgv/w2weRLW02ary/aE+LQ73saaXYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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