SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17494ff96bbadac0f7fc92aab0a0ed983b48457354a128b7bddf44f49d0923d7' 
  AND token = 'GHh2so/wzoWw94d+NWihCY/8IJjYlRne3ZzYBNhh2KA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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