SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aef2d5ca3f15cd9a2a4b6bbc6c2d228f0085c7925966a58eee8d79777243e4e3' 
  AND token = 'y3aIDw8DL5v2CsbrHeMAyobt9aLVHjr2ckPcagNXwzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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