SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '202fb47a3a18745c4249af4aaf4ac4dbd8ef6e9fbd2e715dd01f343ab9e4fedb' 
  AND token = 'IjxO+XnQPPemVtx8h6rXjmdnO8lOQefLeKT6jQRzi5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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