SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ea7384d77525690ced430a7162816402c936462722030c8864903f4f58eef88' 
  AND token = 'gCRlVt0/Ykc1zqpPRyNN9Ipa0aOFwUAZs6NJ7+y1PWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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