SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f23aabea0ed6bca938f7745ac221aea129a898fc08db3b4c0282416587910d78' 
  AND token = 'Gi1LNKDxExst5HOpjxOXGQVXASZdSM/D+qgv7tWg7Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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