SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5a76f83ab1d0b65d0cf6b281e71d8ffc370566270c8888690a942738997888e6' 
  AND token = 'A9OQQ3GxtkPF2NJoqpUlbdmYT/XXFK26DiNghN6XuaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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