SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bc2448569b9fe136c9d87092db53dc8537b5ccc4967c742da33bf598a879f26c' 
  AND token = 'BZijZEvh5L38+Tq71Bfd6odjLQEJgynmOcB18oAaYUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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