SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3df7c8142b373f05f1ea048e0a08b3e4f96125361dccde6567ec3648f35db81b' 
  AND token = '9eQuJZSZMKrU4/iHNotVayH8BWUdLVjcGJIJezhY3bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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