SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35ca5447180bc4ddadbda89900f556a81df26f062f58506abee3628ab93f8132' 
  AND token = 'KDvrrPMjUo/ZMt+V9NY2qoY+MzJmJoHQV48MC3oD+nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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