SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5cacc040f2ec8707455838051ceba1358380c4a09f01c2f670dbbf5753127d9' 
  AND token = 'kaVwSOVgUe7WSMDkKiskOiK80PNRsmUASvWJlswzcO0=' 
  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"
    }
  }
}