SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15141b47eaf92bc392433d36ba511bfacb13de6eae25220b6392d373e5ab7f5d' 
  AND token = 'OAkhhmpfZlP2xJomhyJ22IBGlbwORUg0NhCuZQiGQL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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