SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5f59f18be07b315edde2ad03a7a48397392b7aba3ee91b6e4f40fb3373f4420' 
  AND token = '0YvgTz5Tm+ijW61zY5o/RLaiqshEUgvGZ5lcROZdfhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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