SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bfff5561c908ab69fdf9ced30250f90e147d66c79b4efe757da3a253341430f' 
  AND token = 'YojEmS5NW1wt1IdVsq0yTM/eyg4DNtbvKH9mw28zPr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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