SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '92fc9b511151df06b09db25cafb2b0fa548b0384c8dab825c115c3873e29d8e6' 
  AND token = 'Ew2YbN/GXJ+r4vrI86mS8V3AE4apJdyMClEzjT/2PIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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