SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08a822bd03e700de407464e9afeb5d4197840bdebc5d04f57383b9e47dc5613b' 
  AND token = 'joNvUoPhULimv6nSbNOoJLX5sLqP8IsMDoNbBl9OyPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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