SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66aa7a82be844d42ce6f4627be7b49b1047a7f92d1d5b293722f097ce1da467d' 
  AND token = '+u1IlU7ygNzvLqAaLqWODEa+/EVWi9EbsX+4+TBLB7E=' 
  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"
    }
  }
}