SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac2f5a25bae8c24b04b5094f18ec759309231ab8f37b18a4ce9c02153658f82d' 
  AND token = 'ZUu+bhFaS8Zn95zEEZxiO6BukU4+uVYtoBfATVQfTcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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