SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a284f7d126018b797a9013687fc614168ca2d0fa287677a5ddaa97f125f1ddf1' 
  AND token = 'kvCXA4SkdIJgP0GVdt/tL5N2HpMSfcSWta4s2XFsiaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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