SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93321f34c12eb79144e3922462ba7f7c97c6f90df29635403c92c7d3b0b28f76' 
  AND token = 'Wr8GZPHNngMkiXofO+GyR0+a3WVKWiKeY/qmBXjniEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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