SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16cb5aaac547ed527c7ae3b17736efc459662e0a6eab2726780f0bcc869892f6' 
  AND token = 'PypheX9KJBYpPWdcp30bWE0dDbpFdwCJc5RnduRSRAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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