SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d37afbf28938be221ccba792498a72b767086ef7e07dd7a0ee8ec647f685cb0' 
  AND token = '7g4SeeCIpFe+jsFYex2oeuj07Ohx0qbdcK03lx7yzn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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