SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04a8bdd4b8ca847b358c8b53469d58a451006a790b02ac2e90b5eaa4e9bca94' 
  AND token = 'qhg6LiZDEo4AZMnmJP0QBDbtMwSXV30HfFCVVod/ZGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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