SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9bb123b59d5a8acc80fcd04aa8e8797d9a6e47f709f7b635fd7904d9a9709f8' 
  AND token = '+ggVuqBjTK8DgZN1/pYdSF7kgpAkJcvCLBFZgznHtiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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