SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70fe6a1bdf9b13ef7531d1201235021fdc6c9bb83067adaf20d3c6e4af003783' 
  AND token = 'rvH24GmQnvMjZWXzPYAKvWG4rJFCiMW63mzgqQ/i0oI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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