SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa577b343ccc735022d75ef92201df2cb6c5decfe611776048ee699e014e7927' 
  AND token = 'fNYyv3Ir3BV9zR1NUgXUok2ZlwNoYbtPJuJ3DwFFe8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}