SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7661811e12bf33d5fd83c955c402da57735a879fac381d27ce092fa613d9a87f' 
  AND token = '3XMw2ccc6TpRWbMGVeebqbkn83lbYvvH7xL9fHSEtrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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