SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a305fdeefda3cb13fc71d887da9c4d90f75767e70758b9e31cd6c3a6db98b8cc' 
  AND token = 'qP3ja+yw8ku4MYISGz8Z/8a0H9jpR8Ry5XSpIIjO/O4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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