SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47bb1ac04494f03ddc9e997072c2ac615f7b36efce41a5db4d18d2d80248fa8a' 
  AND token = 'ptUlJaH+icGFeGRsPGK2YWb8LvPgBzEHtJXcZZbF4p0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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