SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '385cd4f82b22a63bdbcf2f11dec9eae5658f6067030c736cacbd9a07882784d4' 
  AND token = 'f3MVVVEuURaNdPMzHmYKRaSvq5IbEyF/xrSaR4VtYNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}