SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '970489211f183d773263dd3329c11aebf186011ec48e76b0dca99e4d90df9208' 
  AND token = 'xM0LnL+ppFTFpYuOzjIaLmX/WVU1KDXjhx7/zEIMywY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}