SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b76a4a0e00a049af27463bfb028f6969dcee88236c53c9252dde0e9a01c004f5' 
  AND token = '13zP1sgk0rYwCT4VtBjluQ7gGRejQgZ9kcE2MkiAm/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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